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(unknown [61.154.14.86]) by smtp.qiye.163.com (Hmail) with ESMTP id 528777a48; Tue, 27 Oct 2026 21:28:35 +0800 (GMT+08:00) From: Damon Ding To: Andrzej Hajda , Neil Armstrong , Robert Foss , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Jingoo Han , Inki Dae , Seung-Woo Kim , Kyungmin Park , Krzysztof Kozlowski , Peter Griffin , Alim Akhtar , Heiko Stuebner , Sandy Huang Cc: Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Dmitry Baryshkov , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-rockchip@lists.infradead.org, Damon Ding Subject: [PATCH v5 17/18] drm/bridge: analogix_dp: Handle HPD notification from downstream bridge Date: Tue, 27 Oct 2026 21:28:09 +0800 Message-Id: <20261027132810.1746118-18-damon.ding@rock-chips.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20261027132810.1746118-1-damon.ding@rock-chips.com> References: <20261027132810.1746118-1-damon.ding@rock-chips.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-HM-Tid: 0aa17d8c66b203a8kunm87c266213d573d X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFITzdXWRgWCB1ZQUpXWS1ZQUlXWQ8JGhUIEh9ZQVkaGk0fVklPSRkfHx5CHRgZHVYVFA kWGhdVEwETFhoSFyQUDg9ZV1kYEgtZQVlNSlVKTk9VSk9VQ01ZV1kWGg8SFR0UWUFZT0tIVUpLSE pKQk1VSktLVUpCWQY+ DKIM-Signature: a=rsa-sha256; b=Z7GrQVafALGYxbl9cufbKo1j2ZtcvouEzvgepU3Jt/FPbxNnrJMpNQZbKIAmWb78Oalpu8T0vbZuDUJVgFrWtxsGNYwjXCS3SDxnkCGtRL7gHQqMPGFV5rkqVccZvR+Zgq/Hk6qtiD7tODFyIxW7rfNtmsw6zLJeZ6lpEAwxc74=; c=relaxed/relaxed; s=default; d=rock-chips.com; v=1; bh=CXfbE7Ybw5a0wreLfpJJMyfqftnRKWN9vP8UgCfupMs=; h=date:mime-version:subject:message-id:from; When the display pipeline includes a display-connector bridge with hpd-gpios configured, the connector's hotplug status is managed by the display-connector bridge through its GPIO, not by the Analogix DP controller's native HPD. In this configuration, the DP controller's internal HPD polling in analogix_dp_detect_hpd() does not reflect the actual connection state. At attach time, detect whether a downstream bridge provides HPD events (DRM_BRIDGE_OP_HPD) while none of them provides detection (DRM_BRIDGE_OP_DETECT). When found, switch to hpd notify mode: cache the connection status reported through the .hpd_notify callback, mute the controller's native HPD interrupts and skip their initialization, and trust the cached status instead of polling the typically unconnected native HPD pin. Suggested-by: Heiko Stuebner Link: https://lore.kernel.org/all/5609825.iZASKD2KPV@diego/ Tested-by: Heiko Stuebner Signed-off-by: Damon Ding --- Changes in v3: - Introduce hpd_notify_mode flag to skip native HPD operations when HPD comes from a downstream bridge. Changes in v4: - Add Tested-by tag. Changes in v5: - Return the connector status directly from analogix_dp_bridge_detect() in the hpd notify mode, to avoid the race where the hpd_notify() echo of the detect path overwrites a newer notification cached by analogix_dp_bridge_notify(). (Sashiko) --- .../drm/bridge/analogix/analogix_dp_core.c | 31 ++++++++++++++++++- .../drm/bridge/analogix/analogix_dp_core.h | 2 ++ .../gpu/drm/bridge/analogix/analogix_dp_reg.c | 7 +++-- 3 files changed, 37 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index 938c70dc8e15..9e6e83357232 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -52,7 +52,8 @@ static const bool verify_fast_training; static bool analogix_dp_require_pm_for_hpd_irq(struct analogix_dp_device *dp) { return (dp->plat_data->dev_type == RK3576_EDP || dp->plat_data->dev_type == RK3588_EDP) && - !dp->hpd_gpiod && !dp->force_hpd && !dp->force_connected_mode; + !dp->hpd_gpiod && !dp->force_hpd && !dp->force_connected_mode && + !dp->hpd_notify_mode; } static void analogix_dp_init_dp(struct analogix_dp_device *dp) @@ -925,6 +926,9 @@ analogix_dp_bridge_detect(struct drm_bridge *bridge, struct drm_connector *conne enum drm_connector_status status = connector_status_disconnected; int ret; + if (dp->hpd_notify_mode) + return connector->status; + if (dp->force_connected_mode) return connector_status_connected; @@ -959,6 +963,21 @@ static bool analogix_dp_bridge_force_connected(struct analogix_dp_device *dp) return force_connected; } +static bool analogix_dp_has_downstream_hpd(struct analogix_dp_device *dp) +{ + bool hpd_bridge = false; + + drm_for_each_bridge_in_chain_from(dp->bridge.next_bridge, bridge) { + if (bridge->ops & DRM_BRIDGE_OP_DETECT) + return false; + + if (bridge->ops & DRM_BRIDGE_OP_HPD) + hpd_bridge = true; + } + + return hpd_bridge; +} + static int analogix_dp_bridge_attach(struct drm_bridge *bridge, struct drm_encoder *encoder, enum drm_bridge_attach_flags flags) @@ -987,6 +1006,7 @@ static int analogix_dp_bridge_attach(struct drm_bridge *bridge, * accurate hotplug state. */ dp->force_connected_mode = analogix_dp_bridge_force_connected(dp); + dp->hpd_notify_mode = analogix_dp_has_downstream_hpd(dp); } return 0; @@ -1283,6 +1303,14 @@ static void analogix_dp_bridge_atomic_post_disable(struct drm_bridge *bridge, DRM_ERROR("Failed to enable psr (%d)\n", ret); } +static void analogix_dp_bridge_notify(struct drm_bridge *bridge, struct drm_connector *connector, + enum drm_connector_status status) +{ + struct analogix_dp_device *dp = to_dp(bridge); + + dp->connection_notified = (status == connector_status_connected); +} + static void analogix_dp_bridge_hpd_enable(struct drm_bridge *bridge) { } @@ -1303,6 +1331,7 @@ static const struct drm_bridge_funcs analogix_dp_bridge_funcs = { .attach = analogix_dp_bridge_attach, .edid_read = analogix_dp_bridge_edid_read, .detect = analogix_dp_bridge_detect, + .hpd_notify = analogix_dp_bridge_notify, .hpd_enable = analogix_dp_bridge_hpd_enable, .hpd_disable = analogix_dp_bridge_hpd_disable, }; diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h index 2ac92b2bac0a..04db14a91074 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h @@ -171,6 +171,8 @@ struct analogix_dp_device { bool fast_train_enable; bool psr_supported; bool force_connected_mode; + bool hpd_notify_mode; + bool connection_notified; u8 dpcd[DP_RECEIVER_CAP_SIZE]; diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c index af5e5a8ec88d..501360a175d5 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c @@ -193,7 +193,7 @@ void analogix_dp_config_interrupt(struct analogix_dp_device *dp) writel(0, dp->reg_base + ANALOGIX_DP_COMMON_INT_MASK_2); writel(0, dp->reg_base + ANALOGIX_DP_COMMON_INT_MASK_3); - if (dp->hpd_gpiod) { + if (dp->hpd_gpiod || dp->hpd_notify_mode) { analogix_dp_mute_hpd_interrupt(dp, HPD_IRQ_ALL); return; } @@ -435,7 +435,7 @@ void analogix_dp_init_hpd(struct analogix_dp_device *dp) { u32 reg; - if (dp->hpd_gpiod) + if (dp->hpd_gpiod || dp->hpd_notify_mode) return; analogix_dp_clear_hotplug_interrupts(dp, HPD_IRQ_ALL); @@ -536,6 +536,9 @@ int analogix_dp_get_plug_in_status(struct analogix_dp_device *dp) if (dp->hpd_gpiod) { if (gpiod_get_value(dp->hpd_gpiod)) return 0; + } else if (dp->hpd_notify_mode) { + if (dp->connection_notified) + return 0; } else { reg = readl(dp->reg_base + ANALOGIX_DP_SYS_CTL_3); if (reg & HPD_STATUS) -- 2.34.1